Method of manufacturing electromagnet, and electromagnet

ABSTRACT

An electromagnet includes a stacked body formed by stacking and thermocompression-bonding a plurality of insulating base materials having thermoplasticity and including wound linear conductors which define a spiral coil. In a region of each of the insulating base materials surrounded by each of the wound linear conductors, each of low mobility members is formed of a material having mobility lower than that of the insulating base materials at a temperature upon thermocompression-bonding of the insulating base materials.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of manufacturing anelectromagnet including a stacked body, and the electromagnet.

2. Description of the Related Art

Conventionally, electromagnets of various structures which are used forvoice coil motors and the like have been disclosed. JP 62-77048 Adiscloses a voice coil motor which includes an electromagnet formed byusing a stacked body.

The electromagnet disclosed in JP 62-77048 A includes a plurality oflayers of insulating base materials on which linear conductors havingspiral shapes when seen from a plan view are formed. The linearconductors which are formed on adjacent insulating base materials in astacking direction and have spiral shapes when seen from a plan view,spiral in opposite winding directions. Inner circumferential ends of apair of linear conductors whose winding directions are opposite areconnected by a conductor which penetrates the insulating base materials.

When thermoplastic resin is used for the insulating base materials tomanufacture an electromagnet of such a structure, the following problemoccurs. FIGS. 12A and 12B are sectional views illustrating the problemof a stacked electromagnet which uses insulating base materials made ofthermoplastic resin. FIG. 12A illustrates a state beforethermocompression bonding, and FIG. 12B illustrates a state after thethermocompression bonding.

First, as illustrated in FIG. 12A, wound linear conductors 301, 302 and303 are formed on surfaces of a plurality of insulating base materials201, 202 and 203. A plurality of insulating base materials 201, 202, 203and 204 (201 to 204) is stacked sandwiching the linear conductors301,302 and 303 between the linear base materials.

In this regard, the insulating base materials 201, 202 and 203 arestacked such that positions of the wound linear conductors 301, 302 and303 overlap when seen from the stacking direction. Thus, the positionsof the wound linear conductors 301, 302 and 303 are overlaid and thewound linear conductors 301, 302 and 303 are successively connected by avia conductor which is not illustrated to form one coil.

However, according to this configuration, when the insulating basematerials 201 to 204 are thermocompression-bonded to form a stacked body20P, the insulating base materials 201 to 204 are thermoplastic andtherefore move.

In this regard, the number of layers (the number of layers of insulatingbase materials 30 the number of layers of linear conductors) which arestacked in a region in which the wound linear conductors 301, 302 and303 are formed is larger than the number of layers (the number of layersof insulating base materials) which are stacked in a region 909surrounded by the wound linear conductors 301, 302 and 303. Hence, whenuniaxial pressing is performed upon thermocompression bonding, apressure to be applied to a region in which the wound linear conductors301, 302 and 303 are formed is larger than a pressure to be applied tothe region 909. Further, the linear conductors 301, 302 and 303 do notmelt at a temperature at which the insulating base materials melt.

Hence, the insulating base material between the linear conductors movesto another region, and thereby changes a positional relationship of eachlinear conductor in each layer. As illustrated in FIG. 12B inparticular, at position at which the linear conductors are formed nearthe region 909, mobility of the insulating base material is great due tothe difference in the number of layers. Hence, the linear conductors301, 302 and 303 move, and the linear conductors 301, 302 and 303 formedin different layers unnecessarily approach each other and causeshort-circuiting with the linear conductors in the different layers insome cases. Further, even when isotropic pressing is performed uponthermocompression bonding, significant movement and deformation occur inthe region 909, and then the linear conductors move.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide an electromagnetmanufacturing method to manufacture a reliable electromagnet whose shapeis stable even in a structure in which insulating base materials ofthermoplastic resin on which wound linear conductors are formed arestacked, and also provide the electromagnet.

A preferred embodiment of the present invention relates to a method ofmanufacturing an electromagnet which is formed bythermocompression-bonding a plurality of insulating base materialshaving wound linear conductors formed thereon and made of thermoplasticresin, and which includes a coil defined by the wound linear conductors,and includes the following features. An electromagnet manufacturingmethod according to a preferred embodiment of the present inventionincludes a step of forming the wound linear conductors on the pluralityof insulating base materials. The electromagnet manufacturing methodincludes a step of arranging a low mobility member whose mobility islower than a mobility of the thermoplastic resin at a temperature uponthe thermocompression-bonding of the thermoplastic resin, in a region ofat least one of the plurality of insulating base materials surrounded byeach of the wound linear conductors. The electromagnet manufacturingmethod includes a step of stacking and thermocompression-bonding theplurality of insulating base materials.

According to this electromagnet manufacturing method, the low mobilitymember prevents movement of thermoplastic resin near the low mobilitymember. Consequently, it is possible to prevent movement of the linearconductors caused by the movement of the thermoplastic resin uponthermocompression bonding. Hence, the positional relationship of thewound linear conductor in each layer hardly changes from a state beforethermocompression bonding, i.e., from a stacking state. Consequently, itis possible to stabilize a shape of the coil defined by the wound linearconductors, and obtain a reliable electromagnet.

Further, according to an electromagnet manufacturing method according toa preferred embodiment of the present invention, preferably, the lowmobility member is made of the same material as a material of the woundlinear conductors, and the step of forming one of the wound linearconductors and the step of arranging the low mobility member aresimultaneously performed.

According to this electromagnet manufacturing method, it is possible tosimultaneously form the low mobility members and the linear conductorsand, consequently, simplify the manufacturing process. Further, theelectromagnet is substantially controlled according to a direct currentsignal and is not controlled according to a high frequency signal.Therefore, even when the low mobility members which are conductors areprovided in regions surrounded by the wound linear conductors whichdefine the coil, an electromagnetic wave generated by the electromagnetis hardly shielded by the low mobility members.

Further, according to the electromagnet manufacturing method accordingto a preferred embodiment of the present invention, preferably, theconductor which defines the low mobility member is formed integrallywith one of the linear conductors provided on the same insulating basematerial.

According to this electromagnet manufacturing method, it is possible tosimplify the manufacturing process and prevent movement of the lowmobility members, too.

Further, an electromagnet manufacturing method according to a preferredembodiment of the present invention is preferably the following method.The conductor which defines the low mobility member is provided on eachof a plurality of insulating base materials. The conductors which definethe low mobility member, being provided on a plurality of insulatingbase materials, are connected each other by a connection conductor whichis elongated in a stacking direction in which the plurality ofinsulating base materials are stacked.

According to this electromagnet manufacturing method, it is possible toprevent movement of the low mobility members, too.

Further, according to an electromagnet manufacturing method according toa preferred embodiment of the present invention, preferably, theconnection conductor which is connected to the low mobility member, anda coil connection conductor which defines the coil together with thewound linear conductors are simultaneously formed.

According to this electromagnet manufacturing method, it is possible tofurther simplify the manufacturing process.

Further, another preferred embodiment of the present invention providesto an electromagnet in which a coil defined by wound linear conductorsand including an axis in a stacking direction is provided in a stackedbody including a plurality of insulating base materials on which thewound linear conductors are located and is made of thermoplastic resin,and includes the following features. In ab electromagnet according to apreferred embodiment of the present invention, a low mobility memberwhose mobility is lower than mobility of the thermoplastic resin at atemperature upon thermocompression-bonding of the thermoplastic resin islocated in a region surrounded by each of the wound linear conductorswhen the stacked body is seen from the stacking direction.

According to this configuration, the low mobility members preventmovement of the insulating base materials made of thermoplastic resin,and therefore movement of the wound linear conductors is also prevented.Hence, the positional relationship of the wound linear conductor in eachlayer hardly changes from a state before thermocompression bonding,i.e., from a stacking state. Consequently, a shape of the coil definedby the wound linear conductors stabilizes.

In case of the electromagnet in particular, as wound linear conductorsare more densely arranged, a greater torque is produced by the compactlinear conductors. However, the linear conductors approach each otherand therefore are likely to cause short-circuiting. Further, a torquebecomes greater as a distance from a coil winding center to each linearconductor in the electromagnet is longer. However, when the distancefrom the coil winding center to the linear conductor is longer, an areasurrounded by the linear conductor becomes larger and each insulatingbase material is more likely to move. However, by using thisconfiguration, it is possible to prevent movement of the insulating basematerials even when the areas surrounded by the linear conductors becomelarger. That is, the configuration according to a preferred embodimentof the present invention more effectively functions for the structure ofthe electromagnet.

Further, according to an electromagnet according to a preferredembodiment of the present invention, preferably, the low mobility memberis made of the same material as a material of the wound linearconductors and is integrally provided with one of the wound linearconductors provided on the same insulating base material.

According to this configuration, the low mobility members and the linearconductors are physically connected. Consequently, it is possible tomore reliably prevent movement of the linear conductors and the lowmobility members caused by movement of the insulating base materials.

Further, in an electromagnet according to a preferred embodiment of thepresent invention, the conductor which defines the low mobility memberis provided on each of a plurality of insulating base materials, and theconductors which define the low mobility member, being provided on aplurality of insulating base materials, may be connected each other by aconnection conductor which is elongated in a stacking direction in whichplurality of insulating base materials are stacked.

According to this configuration, the conductors defining the lowmobility member provided on each insulating base material are physicallyconnected. Consequently, it is possible to more reliably preventmovement of the linear conductors and the low mobility members caused bymovement of the insulating base material.

According to various preferred embodiments of the present invention, itis possible to provide a reliable electromagnet in which insulating basematerials of thermoplastic resin on which wound linear conductors areprovided are stacked, and whose shape is stable.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are an external appearance view and an explodedperspective view of an electromagnet according to a first preferredembodiment of the present invention.

FIG. 2 is a side sectional view of the electromagnet according to thefirst preferred embodiment of the present invention.

FIG. 3 is a flowchart illustrating a flow of manufacturing theelectromagnet according to the first preferred embodiment of the presentinvention.

FIG. 4 is a side sectional view of the electromagnet according toanother aspect of the first preferred embodiment of the presentinvention.

FIG. 5 is an exploded perspective view of the electromagnet according tothe second preferred embodiment of the present invention.

FIG. 6 is an exploded perspective view of the electromagnet according toa third preferred embodiment of the present invention.

FIGS. 7A, 7B, and 7C are views illustrating configurations of a cameramodule which uses the electromagnet according to a preferred embodimentof the present invention.

FIG. 8 is a partially enlarged view illustrating arrangement portions ofa permanent magnet and the electromagnet in the camera module accordingto a preferred embodiment of the present invention.

FIGS. 9A, 9B and 9C are views illustrating a concept of an electromagnetmanufacturing method according to a fourth preferred embodiment of thepresent invention, and are side sectional views of the electromagnetformed by the electromagnet manufacturing method.

FIGS. 10A, 10B and 10C are views illustrating a concept of anelectromagnet manufacturing method according to a fifth preferredembodiment of the present invention, and are side sectional views of theelectromagnet formed by the electromagnet manufacturing method.

FIG. 11 is an exploded perspective view of an electromagnet according toa sixth preferred embodiment of the present invention.

FIGS. 12A and 12B are sectional views illustrating a task of a stackedelectromagnet which uses conventional insulating base materials made ofthermoplastic resin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An electromagnet and an electromagnet manufacturing method according tothe first preferred embodiment of the present invention will bedescribed with reference to the drawings. FIG. 1A is an externalappearance view of the electromagnet according to the first preferredembodiment of the present invention. FIG. 1B is an exploded perspectiveview of the electromagnet according to the first preferred embodiment ofthe present invention. FIG. 2 is a side sectional view of theelectromagnet according to the first preferred embodiment of the presentinvention.

As illustrated in FIGS. 1A and 1B, an electromagnet 10 includes astacked body 20 preferably with a cuboid shape. The stacked body 20 isformed preferably by stacking and thermocompression-bonding a pluralityof insulating base materials 201, 202, 203 and 204 (201 to 204). Aplurality of insulating base materials 201 to 204 is made of sheetthermoplastic resin. The thermoplastic resin is mainly made of, forexample, liquid crystal polymers.

On a surface of the insulating base material 201, a wound linearconductor 301 and a low mobility member 401 of a flat shape are formed.The wound linear conductor 301 has a shape elongated along an outercircumference of the surface of the insulating base material 201. Thelinear conductor 301 is made of a material of high conductivity. Forexample, the linear conductor 301 is made of copper. One end of thelinear conductor 301 is connected to an external connection conductor 31which is provided on the surface of the insulating base material 204 bya coil connection conductor 501 which penetrates the insulating basematerials 202 to 204.

The low mobility member 401 is located in a region surrounded by thewound linear conductor 301. The low mobility member 401 is made of amaterial having mobility lower than that of the insulating base material201 at a thermocompression bonding temperature (e.g., about 250° C. toabout 350° C.) of the insulating base material 201. For example, the lowmobility member 401 is made of the same copper as that of the linearconductor 301. In addition, the low mobility member 401 and the linearconductor 301 are made of the same material, and, consequently, can besimultaneously formed, so that it is possible to simplify amanufacturing process.

On a surface of the insulating base material 202, a wound linearconductor 302 and a low mobility member 402 of a flat shape areprovided. The wound linear conductor 302 has a shape elongated along anouter circumference of the surface of the insulating base material 202.The wound linear conductor 302 partially overlaps the linear conductor301 along an elongation direction when the stacked body 20 is seen fromthe stacking direction. The linear conductor 302 is made of a materialof high conductivity. For example, the linear conductor 302 is made ofcopper.

One end of the linear conductor 302 and the other end of the linearconductor 301 overlap when seen from the stacking direction. The one endof the linear conductor 302 and the other end of the linear conductor301 are connected by a coil connection conductor 502 which penetratesthe insulating base material 202.

The low mobility member 402 is located in a region surrounded by thewound linear conductor 302. The low mobility member 402 partiallyoverlaps the low mobility member 401 when the stacked body 20 is seenfrom the plan view.

The low mobility member 402 is made of a material having mobility lowerthan that of the insulating base material 202 at a thermocompressionbonding temperature of the insulating base material 202. For example,the low mobility member 402 is made of the same copper as that of thelinear conductor 302 and the low mobility member 401. In addition, thelow mobility member 402 and the linear conductor 302 are made of thesame material, and, consequently, can be simultaneously formed, so thatit is possible to simplify a manufacturing process.

On a surface of the insulating base material 203, a wound linearconductor 303, a low mobility member 403 of a flat shape and anintra-layer connection conductor 313 are provided. The wound linearconductor 303 has a shape elongated along an outer circumference of thesurface of the insulating base material 203. The wound linear conductor303 partially overlaps the linear conductors 301 and 302 along theelongation direction when the stacked body 20 is seen from the stackingdirection. The linear conductor 303 is made of a material of highconductivity. For example, the linear conductor 303 is made of copper.

One end of the linear conductor 303 and the other end of the linearconductor 302 overlap when seen from the stacking direction. The one endof the linear conductor 303 and the other end of the linear conductor302 are connected by a coil connection conductor 503 which penetratesthe insulating base material 203.

The low mobility member 403 is located in a region surrounded by thewound linear conductor 303. The low mobility member 403 partiallyoverlaps the low mobility members 401 and 402 when the stacked body 20is seen from the plan view.

The low mobility member 403 is made of a material having mobility lowerthan that of the insulating base material 203 at a thermocompressionbonding temperature of the insulating base material 203. For example,the low mobility member 403 is made of the same copper as that of thelinear conductor 303 and the low mobility members 401 and 402.

The intra-layer connection conductor 313 physically connects the linearconductor 303 and the low mobility member 403. Similar to the lowmobility member 403, the intra-layer connection conductor 313 is made ofa material having mobility lower than that of the insulating basematerial 203 at a thermocompression bonding temperature of theinsulating base material 203. In addition, this intra-layer connectionconductor 313 may be omitted.

The intra-layer connection conductor 313, the linear conductor 303 andthe low mobility member 403 are preferably made of the same material,and are preferably formed integrally. That is, the intra-layerconnection conductor 313, linear conductor 303 and the low mobilitymember 403 are preferably formed in one patterning process. In addition,“simultaneous” formation in the present preferred embodiment means thatmembers are formed together in a step which is commonized. By integrallyforming the intra-layer connection conductor 313, the linear conductor303 and the low mobility member 403, it is possible to prevent aninfluence caused by movement upon thermocompression bonding of theinsulating base material 203 and more effectively prevent movement ofthe linear conductor 303. Further, the intra-layer connection conductor313, the linear conductor 303 and the low mobility member 403 are madeof the same material and are integrally formed, so that it is possibleto simplify the manufacturing process.

On a surface of the insulating base material 204, rectangular orsubstantially rectangular external connection conductors 31 and 32 areprovided. The external connection conductors 31 and 32 are made of amaterial of high conductivity. For example, the external connectionconductors 31 and 32 are made of copper.

The external connection conductor 31 is connected to one end of thelinear conductor 301 by the coil connection conductor 501 as describedabove. The external connection conductor 32 is connected to the otherend of the linear conductor 303 by a coil connection conductor 504 whichpenetrates the insulating base material 204.

According to this configuration, it is possible to provide a spiral coildefined by the linear conductors 301, 302 and 303 and the coilconnection conductors 502, 503 and 504. In this case, a coil windingaxial direction is parallel or substantially parallel to the stackingdirection.

Further, as described in the present preferred embodiment, the lowmobility members 401, 402 and 403 are used, so that, as illustrated inFIG. 2, when the insulating base materials 201 to 204 made ofthermoplastic resin are thermocompression-bonded to form the stackedbody 20, it is possible to prevent the linear conductors 301, 302 and303 from moving.

Consequently, it is possible to provide a reliable coil element whichhas good coil characteristics. Further, according to the configurationaccording to the present preferred embodiment, even when areas ofregions surrounded by the linear conductors are made larger, the lowmobility members 401, 402 and 403 prevent the linear conductors 301, 302and 303 from moving. Consequently, as described in the present preferredembodiment, according to an aspect where the coil element is theelectromagnet 10, it is possible to provide a highly reliableelectromagnet of a great torque.

Further, in case of the electromagnet, as wound linear conductors aremore densely arranged, a greater torque is produced by compact linearconductors. However, the linear conductors approach each other, andtherefore are likely to cause short-circuiting. However, by adopting theconfiguration and the manufacturing method according to the presentpreferred embodiment, it is possible to prevent such short-circuiting.

Further, the electromagnet is substantially controlled according to adirect current signal and is not controlled according to a highfrequency signal. Therefore, even when the low mobility members whichare conductors are provided in regions surrounded by the wound linearconductors which define the coil, an electromagnetic wave generated bythe electromagnet is hardly shielded by the low mobility members.

Further, in the present preferred embodiment, the linear conductor 303and the low mobility member 403 on the surface of the insulating basematerial 203 are connected by the intra-layer connection conductor 313,so that it is possible to further prevent movement of the linearconductors.

The electromagnet 10 with this configuration can be manufactured by thefollowing example manufacturing method. FIG. is a flowchart illustratinga flow of manufacturing the electromagnet according to the firstpreferred embodiment of the present invention.

First, an insulating base material made of thermoplastic resin having aconductor (e.g. copper) formed on a single surface is prepared. Byperforming patterning processing on this insulating base material, aconductor pattern on each of the insulating base materials 201 to 204 inFIG. 1B is formed. More specifically, the linear conductor 301 and thelow mobility member 401 are formed on the insulating base material 201.The linear conductor 302 and the low mobility member 402 are formed onthe insulating base material 202. The linear conductor 303 and the lowmobility member 403 are formed on the insulating base material 203. Thelinear conductor 303 and the low mobility member 403, and theintra-layer connection conductor 313 are formed on the insulating basematerial 203 (S101). In this case, the linear conductor 303, the lowmobility member 403 and the intra-layer connection conductor 313 areintegrally formed.

Further, the external connection conductors 31 and 32 are formed on thefourth insulating base material 204.

Furthermore, at positions at which the coil connection conductors 501,502, 503 and 504 are formed on the insulating base materials 202, 203and 204, a through-hole is formed, and a conductive paste is filled inthe through-holes.

Next, the insulating base materials 201 to 204 on which conductivepatterns have been formed are stacked (S102). In this case, asillustrated in FIG. 1B, the insulating base materials 201 to 204 arestacked such that a coil of a spiral shape whose winding axial directionis parallel or substantially parallel to the stacking direction isformed.

Next, members on which the insulating base materials 201 to 204 havebeen stacked are thermocompression-bonded to form the stacked body 20(S103). In this regard, the low mobility members 401, 402 and 403 areprovided, so that it is possible to prevent the linear conductors 301,302 and 303 from moving and manufacture a reliable electromagnet.

In addition, this manufacturing process is preferably performed in astate of a base material from which a plurality of stacked bodies 20 canbe formed, and, in this case, a plurality of stacked bodies 20 is formedby cutting the base material after thermocompression bonding.

By using the above manufacturing method, it is possible to easily andreliably manufacture the reliable electromagnet. Further, it is possibleto simplify the manufacturing process by simultaneously forming thelinear conductors and the low mobility members on the surfaces of therespective insulating base materials. Furthermore, the linear conductor,the low mobility member and the intra-layer connection conductor on thesurface of the insulating base material 203 are integrally formed, sothat it is possible to simplify the manufacturing process.

In addition, an aspect where the low mobility members preferably areformed on all insulating base materials on which linear conductors havebeen formed has been described in the present preferred embodiment.However, according to another aspect, a low mobility member may beformed on at least one insulating base material. Further, theintra-layer connection conductor may be provided to each insulating basematerial.

The electromagnet with this configuration may employ the followingconfiguration. FIG. 4 is a side sectional view of the electromagnetaccording to another aspect of the first preferred embodiment of thepresent invention.

An electromagnet 10′ illustrated in FIG. 4 additionally includes athrough-hole 60 compared to the electromagnet 10 illustrated in FIGS. 1and 2. Hence, only differences from the electromagnet 10 will bedescribed.

The through-hole 60 penetrates the stacked body 20 in the stackingdirection. The through-hole 60 is provided in a region in which the lowmobility members 401, 402 and 403 overlap when the stacked body 20 isseen from the stacking direction.

By providing this through-hole 60, it is possible to easily fix theelectromagnet 10′ by using a screw inserted through the through hole 60.Further, the low mobility members 401, 402 and 403 are provided, so thata strength of the region of the stacked body 20 provided with thethrough-hole 60 increases, and it is possible to prevent a damage causedupon screwing. Furthermore, it is possible to highly strongly fix theelectromagnet 10′. Still further, the linear conductors are preventedfrom being misaligned, so that it is possible to prevent misalignment ofthe linear conductors from moving the through-hole 60 to the positionsof the linear conductors when the through-hole 60 is provided. That is,it is possible to prevent the linear conductors from being cut bymistake.

Next, an electromagnet according to the second preferred embodiment ofthe present invention will be described with reference to the drawings.FIG. 5 is an exploded perspective view of the electromagnet according tothe second preferred embodiment of the present invention.

An electromagnet 10A according to the present preferred embodimentadditionally includes a fixing inter-layer connection conductor 70without an inter-layer connection conductor 313 compared to anelectromagnet 10 according to the first preferred embodiment. A basicmethod of manufacturing the electromagnet 10A according to the presentpreferred embodiment is also the same as the electromagnet 10 accordingto the first preferred embodiment. Hereinafter, only differences fromthe electromagnet 10 according to the first preferred embodiment will bespecifically described.

As illustrated in FIG. 5, the electromagnet 10A includes the fixinginter-layer connection conductor 70. The fixing inter-layer connectionconductor 70 has a shape which penetrates insulating base materials 202and 203 and a low mobility member 402. The fixing inter-layer connectionconductor 70 physically connects low mobility members 401, 402 and 403.

By using the fixing inter-layer connection conductor 70, it is possibleto fix the low mobility members 401, 402 and 403 even uponthermocompression bonding of insulating base materials 201 to 204.Consequently, it is possible to form the more reliable electromagnet10A.

This inter-layer connection conductor 70 can be formed in one process offorming a through-hole and a connection conductor together with coilconnection conductors 501, 502, 503 and 504 according to the samemanufacturing method as the coil connection conductors 501, 502, 503 and504. In addition, “simultaneous” formation in the present preferredembodiment means that members are formed together in a step which iscommonized. Thus, by forming the inter-layer connection conductor 70 inthe same process as that of the coil connection conductors 501, 502, 503and 504, it is possible to manufacture the electromagnet 10A in a moresimple manufacturing process.

In addition, an aspect where all low mobility members 401, 402 and 403are connected with the inter-layer connection conductor 70 has beendescribed in the present preferred embodiment. According to anotheraspect, at least two low mobility members may be connected.

Next, an electromagnet according to the third preferred embodiment ofthe present invention will be described with reference to the drawings.FIG. 6 is an exploded perspective view of the electromagnet according tothe third preferred embodiment of the present invention.

An electromagnet 10B according to the present preferred embodimentadditionally includes a low mobility member 410 and through-holes 422and 423 without an intra-layer connection conductor 313 and low mobilitymembers 401, 402 and 403 compared to an electromagnet 10 according tothe first preferred embodiment. A basic method of manufacturing theelectromagnet 10B according to the present preferred embodiment is alsothe same as the electromagnet 10 according to the first preferredembodiment. Hereinafter, only differences from the electromagnet 10according to the first preferred embodiment will be specificallydescribed.

On a surface of an insulating base material 201, the low mobility member410 having a height equal to or more than thicknesses ofthermocompression-bonded insulating base materials 202 and 203 isarranged. In a region of the insulating base material 202 which overlapsan arrangement region of the low mobility member 410, the through-hole422 is formed. In a region of the insulating base material 203 whichoverlaps an arrangement region of the low mobility member 410, thethrough-hole 423 is formed.

According to this configuration, when the insulating base materials 201to 204 are stacked, the low mobility member 410 fits in the throughholes 422 and 423. Further, by performing thermocompression bonding inthis stacking state, it is possible to prevent the linear conductors301, 302 and 303 from moving.

In addition, in the present preferred embodiment, the low mobilitymember 410 may be made of a material which is a magnetic core of theelectromagnet 10B. Consequently, it is possible to improve performanceof the electromagnet. The material which is the magnetic core is, forexample, metal such as permalloy or ferrite.

Further, each low mobility member described in each of the abovepreferred embodiments may be made of a material which becomes a magneticcore of the electromagnet unless each low mobility member is integrallyformed with each linear conductor, and may be made of a so-called dummymember which simply includes an insulation property and has lowmobility.

Next, one aspect of an electronic device module which uses anelectromagnet according to each of the above preferred embodiments ofthe present invention will be described. FIGS. 7A, 7B, and 7C are viewsillustrating configurations of a camera module which uses theelectromagnet according to a preferred embodiment of the presentinvention. FIG. 7A is a plan view of a camera module. FIG. 7B is a sideview of a default state of the camera module. FIG. 7C is a side view ofa driven state of the camera module. FIG. 8 is a partially enlarged viewillustrating arrangement portions of a permanent magnet and theelectromagnet in the camera module.

A camera module 800 includes a plurality of electromagnets 10. Aplurality of electromagnets 10 is provided in a base substrate 200.

On a surface of the base substrate 200, a frame 80 is arranged. Theframe 80 is slidably arranged on the base substrate 200.

The frame 80 is provided with an opening which is not illustrated, and alens holder 81 is inserted in the opening. The lens holder 81 is fixedto the frame 80. A lens 82 is fixed to an end portion of the lens holder81 at an opposite side to a base substrate 200 side.

On the surface of the frame 80, a plurality of permanent magnets 83 isarranged so as to surround the lens holder 81. More specifically, thetwo permanent magnets 83 are arranged along a first direction on thesurface of the frame 80 to sandwich the lens holder 81. Further, the twopermanent magnets 83 are arranged along a second direction perpendicularor substantially perpendicular to the first direction on the surface ofthe frame 80 to sandwich the lens holder 81.

A plurality of permanent magnets 83 is arranged to face theelectromagnets 10 across the frame 80. A plurality of permanent magnets83 is connected to the base substrate 200 through wires 84.

According to such a configuration, by applying a current to thepredetermined electromagnet 10, an electromagnetic force is applied andthe base substrate 200 slides with respect to the frame 80. This slidemoves the position of the lens 82. That is, it is possible to define avoice coil motor of the camera.

In addition, when the base substrate 200 is thick, the electromagnets 10are preferably formed near the surface at the frame 80 side. By formingthe electromagnets 10 at these positions, it is possible to realize thecamera module 800 more efficiently drives the voice coil motor.

Further, by using the above electromagnets, it is possible to realizethe reliable camera module 800.

Furthermore, an aspect where conductors are used as low mobility membershas been described in the above preferred embodiment.

However, each low mobility member may be made of ceramics orthermoplastic resin.

An aspect where the low mobility members are left in the stacked bodyhas been described in each of the above preferred embodiments. However,the following manufacturing method may be used for an aspect where thelow mobility members are not left in the stacked body.

Next, an electromagnetic manufacturing method and an electromagnetaccording to the fourth preferred embodiment of the present inventionwill be described with reference to the drawings. FIGS. 9A, 9B and 9Care views illustrating a concept of the electromagnet manufacturingmethod according to the fourth preferred embodiment of the presentinvention, and are side sectional views of the electromagnet formed bythe electromagnet manufacturing method.

As illustrated in FIG. 9A, a wound linear conductor 301C is formed onthe surface of an insulating base material 201. In a region of theinsulating base material 201 surrounded by the wound linear conductor301C, a through-hole 601 is provided.

A wound linear conductor 302C is formed on the surface of an insulatingbase material 202. In a region of the insulating base material 202surrounded by the wound linear conductor 302C, a through-hole 602 isprovided.

A wound linear conductor 303C is formed on the surface of an insulatingbase material 203. In a region of the insulating base material 203surrounded by the wound linear conductor 303C, a through-hole 603 isprovided.

As illustrated in FIG. 9A, the insulating base materials 201, 202 and203 are stacked such that surfaces of the insulating base materials 201,202 and 203 are parallel or substantially parallel. In this regard, theinsulating base materials 201, 202 and 203 are stacked such thatpositions of the through-holes 601, 602 and 603 match.

Stamps 491 and 492 are pressed against the insulating base materials201, 202 and 203 stacked in this way, from both sides in the stackingdirection. In this regard, the stamp 491 comes into contact with theinsulating base material 201 side, and the stamp 492 comes into contactwith the insulating base material 203 side. An elastic body 493 isattached between the stamp 492 and the insulating base material 203. Theelastic body 493 is made of a material which does not melt at athermocompression bonding temperature of the insulating base materials201, 202 and 203.

The stamps 491 and 492 are made of a material (low mobility material)such as metal having mobility lower than that of the insulating basematerials 201, 202 and 203 at a temperature uponthermocompression-bonding of the insulating base materials 201, 202 and203.

The stamp 491 includes a flat main body 4911 and a convex portion 4912having a shape which projects from a flat surface of the main body 4911.The main body 4911 and the convex portion 4912 may be integrally formedor may be separately formed. When the main body 4911 and the convexportion 4912 are separately formed, materials for the main body 4911 andthe convex portion 4912 may be different yet are low mobility members.

The stamp 492 is a flat plate.

The stamp 491 is pressed against the stacked insulating base materials201, 202 and 203 such that the convex portion 4912 is inserted in thethrough-holes 601, 602 and 603.

By performing thermocompression bonding in this state, the insulatingbase materials 201, 202 and 203 melt and adhere to each other asillustrated in FIG. 9B. In this regard, the convex portion 4912 of thestamp 491 is inserted in the through-holes 601, 602 and 603, so that theconvex portion 4912 stops movement of the insulating base materials 201,202 and 203.

By detaching the stamps 491 and 492 and the elastic body 493 after thisthermocompression bonding, a stacked body 20C is formed and anelectromagnet 10C is formed as illustrated in FIG. 9C. In a region ofthe stacked body 20C surrounded by the wound linear conductors 301C,302C and 303C, a through-hole 60C is provided.

Thus, even when a portion of the stamps which thermocompression-bond theinsulating base materials 201, 202 and 203 are the above low mobilitymembers, it is possible to prevent the insulating base materials frommoving upon thermocompression bonding.

In addition, as described in the present preferred embodiment, theelastic body 493 deforms to alleviate a difference between a height(thickness) of the convex portion 4912 and a thickness of thethermocompression-bonded insulating base materials 201, 202 and 203 byusing the elastic body 493 upon thermocompression bonding. Thus, theentire insulating base materials 201, 202 and 203 arethermocompression-bonded at an equal pressing pressure. Consequently, itis possible to more reliably form the stacked body 20C in a desiredshape.

Next, an electromagnetic manufacturing method and an electromagnetaccording to the fifth preferred embodiment of the present inventionwill be described with reference to the drawings. FIGS. 10A, 10B and 10Care views illustrating a concept of the electromagnet manufacturingmethod according to the fifth preferred embodiment of the presentinvention, and are side sectional views of the electromagnet formed bythe electromagnet manufacturing method.

An electromagnet 10D according to the present preferred embodimentdiffers from an electromagnet 10C according to the fourth preferredembodiment in a structure of a stacked body 20D. Accordingly, a portionof the manufacturing method is also different.

As illustrated in FIG. 10A, the stacked body 20D includes insulatingbase materials 201, 202, 203 and 204. The insulating base materials 201,202 and 203 are the same as those of the stacked body 20C according thefourth preferred embodiment. The insulating base material 204 has nolinear conductor provided thereon, and is not provided with athrough-hole, either. The insulating base material 204 is arranged onthe surface of the insulating base material 203.

According to this configuration, a surface at a distal end of a convexportion 4912 of a stamp 491 comes into contact with the insulating basematerial 204. As illustrated in FIG. 10B, in this state, the stackedinsulating base materials 201, 202, 203 and 204 are sandwiched by stamps491 and 492 and are thermocompression-bonded.

By detaching the stamps 491 and 492 after this thermocompressionbonding, the stacked body 20D is formed and the electromagnet 10D isformed as illustrated in FIG. 10C. In a region of the stacked body 20Dsurrounded by wound linear conductors 301D, 302D and 303D, a concaveportion 61 is provided. The concave portion 61 is opened in an outersurface of the stacked body 20D at the insulating base material 201side, and is not opened in an outer surface at the insulating basematerial 204 side.

Even this configuration is able to provide the same function andoperation as those of the fourth preferred embodiment.

Further, according to the configuration of the present preferredembodiment, the insulating base material 204 which is not provided witha linear conductor and a through-hole contributes to uniform applicationof a pressure upon thermocompression bonding similar to the elastic body493 according to the fourth preferred embodiment. Consequently, it ispossible to provide the same function and effect as those of the fourthpreferred embodiment in this regard, too.

Next, an electromagnet according to the sixth preferred embodiment ofthe present invention will be described with reference to the drawings.FIG. 11 is an exploded perspective view of the electromagnet accordingto the sixth preferred embodiment of the present invention.

An electromagnet 10E according to the present preferred embodiment canbe formed the manufacturing method according to the fifth preferredembodiment.

The electromagnet 10E according to the present preferred embodimentincludes a stacked body 20E. The stacked body 20E is formed preferablyby stacking insulating base materials 201, 202, 203 and 204.

On a back surface of the insulating base material 201, externalconnection conductors 31 and 32 are formed. A wound linear conductor302E having a shape which extends along an outer circumference of theinsulating base material 202 is formed on the surface of an insulatingbase material 202. A wound linear conductor 303E having a shape whichextends along an outer circumference of the insulating base material 203is formed on the surface of an insulating base material 203. A woundlinear conductor 304E having a shape which extends along an outercircumference of the insulating base material 204 is formed on thesurface of an insulating base material 204.

One end of the linear conductor 304E is connected to the externalconnection conductor 31 by a coil connection conductor 501E whichpenetrates the insulating base materials 201, 202, 203 and 204. Theother end of the linear conductor 304E is connected to one end of thelinear conductor 303E through by a coil connection conductor 502E whichpenetrates the insulating base material 204. The other end of the linearconductor 303E is connected to one end of the linear conductor 302Ethrough a coil connection conductor 503E which penetrates the insulatingbase material 203. The other end of the linear conductor 302E isconnected to the external connection conductor 32 through a coilconnection conductor 504E which penetrates the insulating base materials201 and 202.

At a portion of the stacked body 20E corresponding to the insulatingbase materials 201 and 202, and in a region surrounded by the linearconductor 302E, the concave portion 61 is provided.

Further, at a portion of the stacked body 20E corresponding to thesurface of the insulating base material 203, an alignment mark 300 isprovided. The alignment mark 300 is a material which provides a desiredcontrast from insulating base materials, and is made of, for example,the same material as that of the linear conductor 303E. When the samematerial as that of the linear conductor 303E is used, it is possible tosimultaneously form the alignment mark 300 and the linear conductor303E, so that it is possible to simplify the manufacturing process.

The alignment mark 300 is preferably located in a region which overlapsthe concave portion 61E when the stacked body 20E is seen from thestacking direction. That is, the alignment mark 300 is preferablylocated in a thin region of the stacked body 20E. By arranging thealignment mark 300 in such a thin region, it is possible to easilyrecognize the alignment mark 300 when mounting the electromagnet 10E onanother circuit board. Consequently, it is easy to align theelectromagnet 10E to arrange, and prevent misalignment. Consequently, itis possible to increase precision to mount the electromagnet 10E onanother circuit board, and more reliably mount the electromagnet 10E.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A method of manufacturing an electromagnet whichis formed by thermocompression-bonding a plurality of insulating basematerials made of thermoplastic resin including wound linear conductorsformed thereon, and which includes a coil defined by the wound linearconductors, the method comprising: a step of forming the wound linearconductors on the plurality of insulating base materials; a step ofarranging a low mobility member with a mobility that is lower than amobility of the thermoplastic resin at a temperature during thethermocompression-bonding of the thermoplastic resin, in a region of atleast one of the plurality of insulating base materials surrounded by atleast one of the wound linear conductors; and a step of stacking andthermocompression-bonding the plurality of insulating base materials;wherein the low mobility member is a conductor made of a same materialas a material of the wound linear conductors; and the step of formingone of the wound linear conductors and the step of arranging the lowmobility member are simultaneously performed.
 2. The method ofmanufacturing the electromagnet according to claim 1, wherein theconductor which defines the low mobility member is formed integrallywith one of the wound linear conductors provided on a same one of theinsulating base materials.
 3. The method of manufacturing theelectromagnet according to claim 1, wherein the conductor which definesthe low mobility member is provided on each of a plurality of insulatingbase materials; and the conductors which define the low mobility member,being provided on a plurality of insulating base materials, areconnected each other by a connection conductor which is elongated in astacking direction in which the plurality of insulating base materialsare stacked.
 4. The method of manufacturing the electromagnet accordingto claim 3, wherein the connection conductor which is connected to thelow mobility member, and a coil connection conductor which connects thewound linear conductors provided on the plurality of insulating basematerials and which defines the coil together with the wound linearconductors are simultaneously formed.
 5. The method of manufacturing theelectromagnet according to claim 1, wherein the temperature during thethermocompression-bonding of the thermoplastic resin is about 250° C. toabout 350° C.
 6. The method of manufacturing the electromagnet accordingto claim 1, wherein the low mobility member is formed simultaneously inthe step of forming the wound linear conductors.
 7. The method ofmanufacturing the electromagnet according to claim 1, wherein at leastone of the linear conductors at least partially overlaps another one ofthe liner conductors in a stacking direction in which the plurality ofinsulating base materials are stacked.
 8. The method of manufacturingthe electromagnet according to claim 1, wherein in the step of arrangingthe low mobility member, a plurality of the low mobility members arearranged, and the method further comprises the step of forming a fixinginter-layer connection conductor that connects the plurality of lowmobility members.
 9. The method of manufacturing the electromagnetaccording to claim 1, wherein the plurality of insulating base materialsinclude a through hole and the low mobility member is arranged in thethrough hole.
 10. The method of manufacturing the electromagnetaccording to claim 1, wherein one of the plurality of insulating basematerials does not include any through hole and does not include any ofthe wound linear conductors.
 11. The method of manufacturing theelectromagnet according to claim 1, wherein a stamp which is used forthe thermocompression-bonding includes a stamp including a convexportion; and the low mobility member is a convex portion.
 12. The methodof manufacturing the electromagnet according to claim 11, wherein thestamp which is used for the thermocompression-bonding includes adifferent stamp; and at least one of the plurality of insulating basematerials is sandwiched between the stamp including the convex portionand the different stamp.
 13. An electromagnet comprising: a coil definedby wound linear conductors and including an axis in a stacking directionof a stacked body including a plurality of insulating base materialsmade of thermoplastic resin on which the wound linear conductors areprovided; and a low mobility member with a mobility lower than amobility of the thermoplastic resin at a thermocompression-bondingtemperature of the thermoplastic resin located in a region surrounded byeach of the wound linear conductors when the stacked body is seen fromthe stacking direction; wherein the low mobility member is a conductormade of a same material as a material of the wound linear conductors.14. The electromagnet according to claim 13, wherein the low mobilitymember is integral with one of the wound linear conductors provided on asame one of the insulating base materials.
 15. The electromagnetaccording to claim 13, wherein conductors which define the low mobilitymember are provided on respective ones of the plurality of insulatingbase materials; and the conductors which define the low mobility memberare connected each other by a connection conductor which is elongated ina stacking direction in which the plurality of insulating base materialsare stacked.
 16. An electronic device module comprising theelectromagnet according to claim
 13. 17. The electronic device moduleaccording to claim 16, further comprising a camera module including abase substrate, wherein the electromagnet is located in the basesubstrate.
 18. The electronic device module according to claim 17,wherein the camera module includes: a plurality of the electromagnets onthe base substrate; and a frame slidably arranged on the base substrateand including an opening, and a lens holder located in the opening; andthe camera module further comprises a plurality of permanent magnetssurrounding the lens holder.